1. Field
This invention relates broadly to bed construction and in particular to spring suspension systems and supports for beds or bunks which are used in the sleeping compartments of the cabs of large, diesel powered trucks.
2. State of the Art
Most large, diesel powered trucks used in interstate or long distance hauling are provided with a sleeping compartment or berth. It has become common in long distance operations to provide two drivers who alternate between sleeping and driving. It is desirable that the non-driving member of the driving team can obtain restful sleep while the other member does the driving and vice versa.
To provide restful sleep while the truck is in operation, various systems have been proposed to insulate the mattress of the bunk and the person lying on the mattress from sleep disrupting movements of the truck. Various systems have been proposed in the past to accomplish this purpose. In U.S. Pat. No. 4,107,797 (Maxwell) issued on Aug. 22, 1978, a system was disclosed which utilized a lower frame, an intermediate frame and an upper frame. A set of rollers are provided for limited fore-and-aft movement of the intermediate frame with respect to the lower frame, and a system of springs dampens the fore-and-aft movement. A hydraulic dampening system is also provided between the upper and intermediate frames and serves to dampen the up and down movement of the upper frame relative to the intermediate frame.
In. U.S. Pat. No. 3,760,436 (Zach) issued on Sept. 25, 1973, a mattress suspension system is disclosed which includes a horizontal mattress tray which is coupled to a support system by a group of vertically oriented straps. The straps allow the mattress tray to swing in a fore-and-aft direction. The support system itself comprises a scissor linkage which is biased by an air spring to dampen the up and down movement of the truck cab relative to the mattress tray.
The suspension systems proposed in the above-mentioned patents are bulky, complicated and costly. A number of other suspension systems which are highly complicated mechanically are disclosed in U.S. Pat. Nos. 3,882,558 (Christensen), 3,371,359 (Dome), 3,299,447 (Dome) and 3,067,437 (Campbell).
Other less relevant prior art includes U.S. Pat. Nos. 3,698,022 (Knight) and 3,902,205 (Bell).
3. Objectives
A principal objective of the present invention is to provide a generally inexpensive bed or bunk to be used in the sleeper compartments of large, diesel powered trucks.
Another objective is to provide an improved mattress suspension system which substantially reduces vibration and other disruptive movements of the truck, and wherein the mattress suspension system is built into a bed or bunk which is quickly and easily installed within and removed from the sleeper compartment of a large, diesel powered truck.
A further objective is to provide a bed or bunk having an improved mattress suspension system and which is simple and inexpensive in its construction and inherently durable and reliable.